The term "Japanese military" refers to the collective armed forces of Japan. They include the Army, Navy, Air Force, and Maritime Self-Defense Force. In addition, there are several synonyms that can be used to describe the Japanese military. These include the Japanese Armed Forces, Japanese Defense Forces, Imperial Japanese Army, Imperial Japanese Navy, and Japan Self-Defense Forces. The usage of each synonym varies according to the historical context in which it is used. For instance, the term Imperial Japanese Army refers to the military forces of Japan during the period of Japan's World War II expansion, while the Japan Self-Defense Forces refers to the post-World War II era.